FC_SpeedTorqueCurve - General Information

Overview

Task

Limit the speed of the axis depending on the torque of the motor shaft (torque-dependent speed limitation). This is required to seal bottles, for example.

Description

In order to solve the task, a torque-speed characteristic curve was implemented to limit the speed in accordance with the current which is proportional to the torque of the motor.

 

 

The values entered for the curve are absolute values which are only configured in the first quadrant.

This automatically gives you the characteristic curves for quadrants 2 to 4, whereas the application of the limits is only useful for quadrants 1 and 3. An unstable behavior occurs in both the other quadrants.

To parameterize the characteristic curve for the i_stAxisId axis, a maximum torque lrTorque1 (x-axis) is specified for a starting speed of rotation lrVelocity1 (y-axis). This determines the first point on the curve. A minimum speed, lrVelocity2, and a corresponding torque, lrTorque2, are also specified.

The torques are entered in Nm. The speed of rotation is entered in unit/s.

The curve is a straight line which passes through the first point and ends at the second point.

From this second point on, the curve runs parallel to the torque axis (x-axis).

When the minimum speed (second point) is reached, the speed is constantly limited to this minimum even if the torque rises.

The "torque-dependent speed limitation" function is only prepared with this function.

The function is activated via SpeedTorqueCurveOn() in "real-time" and de-activated again via SpeedTorqueCurveOff() in "real-time".

This distinguishes the function from SpeedTorqueCurveSet().

NOTE: When using this function, the diagnostic message 8132 "Tracking deviation exceeded" or 8111 "Shutdown due to tracking deviation" may occur.

This is due to your intervention with the control using this function (torque-dependent speed limitation).

The diagnostic messages can be influenced via the parameters FollowingLimit and Pos_P_Gain.

Interface

Return Value